(4-Nitrophenyl)methanesulfonamide → 1-(4-Aminophenyl)methanesulfonamide

5.0 g (23.1 mmol) of 4-nitrophenylmethanesulfonamide was suspended in 90% acetic acid, which was then hydrogenated at normal temperature under normal pressure in the presence of palladium-carbon. After filtering off the catalyst, the filtrate was concentrated to dryness, to give 4.3 g of 4-aminophenylmethanesulfonamide. The obtained compound was added to a mixed solution of 40 ml of water and 4.1 ml of concentrated hydrochloric acid, followed by stirring. An aqueous saturated solution containing 1.63 g (23.6 mmol) of sodium nitrite was added dropwise there into at 0° C. or less. The reaction solution was added to an acetic acid solution saturated with sulfur dioxide (solution obtained by saturating 30 ml of acetic acid with sulfur dioxide and then adding 0.97 g of cupric chloride.dihydrate thereto) under ice-cooling with stirring. After stirring at room temperature for 40 minutes, the reaction solution was poured into ice-water and the mixture was saturated with sodium chloride. The mixture was extracted with ethyl acetate, and the extract was dried over magnesium sulfate and then concentrated to dryness, to give 1.7 g of the title compound.

1. filtrationAfter filtering off the catalyst
2. concentrationthe filtrate was concentrated to dryness

ORD record

ord-fadc4adb98264f9eb7d1ec62b9321b51

Source dataset

uspto-grants-2010_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07834049B2